strobe light troubleshooting

what would be the most common reason that my camera just is not picking up the strobe lighting?? when i take the picture, it's as if the strobes aren't even there..........when i used to take pics with the strobe lights, i used to have to almost cut them down by a 1/2 or a 1/4, but now they are full strength and it's as if it's not even registering that they are there..........

for use with strobes, what are my optimal shutter speeds and aperature. i am not shooting faster than 1/60
this is totally mind boggling.....what setting might have changed on my camera that is not allowing it to even read the strobe lights? i'm a beginner with the strobe lights, and just need to know what things i might want to check to troubleshoot.

I use a digital Olympus E-10 and a hot-shoe for the light connection.

HELP.

Have you always used the E-10 with your strobes? You say your connecting with a hotshoe. Does that mean you have a cable going from the hotshoe to your strobes? Or are you using a flash, on your camera's hotshoe? What exposure mode are you using? Some cameras limit your options in some exposure modes. Your shutter speed should be fine. Have you tried opening up your aperture? For flash photography, the general rule is that the aperture controls your flash exposure and the shutter speed controls the ambient light. Try opening up your aperture and see if you start seeing the strobe.

What do your exposures look like, anyway? Are they too dark? Can you post a sample?